Chair, control method, and program

Abstract

To provide a chair, a control method, and a program capable of effectively training anti-gravity muscles necessary for a user to maintain a posture unconsciously.SOLUTION: A chair 100 according to the present disclosure includes: a base 1; a seating surface 2 positioned on an upper side of the base 1 and seated by a user; an elastic support 31 that connects the base 1 to the seating surface 2, keeps the seating surface 2 in a reference state, and allows the seating surface 2 to tilt from the reference state in response to the force applied to the seating surface 2 by the user's seating; a rotating platform 32 that is installed on an upper side of the base 1 and rotates around a vertical axis on the basis of power; a plurality of support posts 33 of different lengths in a vertical direction that are installed on an upper side of the rotating platform 32 and support the seating surface 2 at an upper end when the seating surface 2 is tilted; and a motor 5 that generates the power.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present disclosure relates to a chair, a control method, and a program.

Background Art

[0002] Patent Document 1 discloses a chair that induces movement of a user's trunk by changing the seat surface in all circumferential directions while fixing the seat surface to be inclined in a predetermined direction. Patent Document 1 also discloses a chair that generates an inclination of the seat surface while the user is inclined by connecting the pedestal and the seat surface with a free joint.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the chair according to Patent Document 1, since the inclination of the seat surface is fixed, it is expected that only the muscles for creating a specific posture of the user will be strained. Further, in the chair, since the inclination of the seat surface is determined by the user's posture, it is expected that the degree of muscle activation with respect to the inclination will be limited. Therefore, the chair according to Patent Document 1 has a problem that a plurality of antigravity muscles necessary for the user to effectively train to maintain the posture unconsciously cannot be trained.

[0005] In view of such problems, an object of the present disclosure is to provide a chair, a control method, and a program that can effectively train a plurality of antigravity muscles necessary for a user to maintain a posture unconsciously.

Means for Solving the Problems

[0006] The chair of the present disclosure is A base, a seat surface located above the base on which a user sits, an elastic support column that connects the base and the seat surface, keeps the seat surface in a reference state, and allows the seat surface to tilt from the reference state in response to the force applied to the seat surface by the user's sitting, a turntable installed above the base and rotating around a vertical axis based on power, a plurality of support columns with different lengths in the vertical direction, installed above the turntable and supporting the seat surface at the upper end when the seat surface tilts, and a motor that generates the power.

[0007] The control method of the present disclosure is a computer controlling the rotation of the motor of a chair comprising a base, a seat surface located above the base on which a user sits, an elastic support column that connects the base and the seat surface, keeps the seat surface in a reference state, and allows the seat surface to tilt from the reference state in response to the force applied to the seat surface by the user's sitting, a turntable installed above the base and rotating around a vertical axis based on power, a plurality of support columns with different lengths in the vertical direction, installed above the turntable and supporting the seat surface at the upper end when the seat surface tilts,

[0008] The program of the present disclosure is a base, a seat surface located above the base on which a user sits, an elastic support column that connects the base and the seat surface, keeps the seat surface in a reference state, and allows the seat surface to tilt from the reference state in response to the force applied to the seat surface by the user's sitting, a turntable installed above the base and rotating around a vertical axis based on power, A plurality of support columns with different lengths in the vertical direction, which are installed above the turntable and support the seat surface at the upper end when the seat surface is inclined, Causing a computer to execute a process of controlling the rotation of the motor of a chair including the motor that generates the power.

Effect of the Invention

[0009] According to the present disclosure, it is possible to provide a chair, a control method, and a program that can effectively train a plurality of antigravity muscles necessary for a user to maintain a posture unconsciously.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

Figure 15

Figure 16

Figure 17

Mode for Carrying Out the Invention

[0011] Hereinafter, specific embodiments to which the present disclosure is applied will be described in detail with reference to the drawings. In each drawing, the same reference numerals are assigned to the same elements, and redundant descriptions are omitted as necessary for clarity of explanation.

[0012] (First Embodiment) First, the configuration of the chair 100 according to the first embodiment will be described with reference to FIGS. 1 to 4. FIG. 1 is a diagram showing an example of the configuration of the chair 100. As shown in FIG. 1, the chair 100 includes a base 1, a seat surface 2, a support mechanism 3, a power transmission mechanism 4, a motor 5, and a controller 6.

[0013] The base 1 is a base on which the components of the chair 100 are mounted. The seat surface 2 is a seat surface on which the user sits. The support mechanism 3 is a mechanism that intervenes between the base 1 and the seat surface 2 and supports the seat surface 2. When the user is not sitting on the seat surface 2, the support mechanism 3 keeps the seat surface 2 in a reference state. The reference state is, for example, a state parallel to the horizontal plane (xy plane). When the user sits on the seat surface 2, the support mechanism 3 allows the inclination of the seat surface 2 from the reference state and further changes the direction allowing the inclination over time around an axis in the vertical direction (z-axis direction). Specifically, the support mechanism 3 has the configuration shown in FIG. 2.

[0014] FIG. 2 is a diagram showing an example of the configuration of the support mechanism 3 of the chair 100. As shown in FIG. 2, the support mechanism 3 includes an elastic body column 31, a turntable 32, and a plurality of support columns 33. For example, the support mechanism 3 includes three elastic body columns 31a, 31b, and 31c as the elastic body column 31. Also, the support mechanism 3 includes three support columns 33a, 33b, and 33c as the plurality of support columns 33.

[0015] The elastic body column 31 is a columnar member having elasticity that connects the base 1 and the seat surface 2. The elastic body column 31 keeps the seat surface 2 in a reference state (for example, a state parallel to the xy plane, that is, a horizontal state) and allows the seat surface 2 to incline from the reference state in response to the force applied to the seat surface 2 when the user sits on the seat surface 2.

[0016] The turntable 32 includes a rotating part 321, a gear part 322, and a rotating base part 323. The rotating part 321 is, for example, a disk-shaped member, and is installed on the rotating base part 323 so as to rotate around the vertical direction (z-axis direction) according to the rotation of the gear part 322. The gear part 322 is, for example, a pulley that interlocks with the rotating part 321, and teeth for attaching a belt or the like for receiving power from the power transmission mechanism 4 are provided on the outer peripheral surface. Further, the turntable 32 includes a through-hole (not shown) through which the elastic body support column 31 penetrates.

[0017] The support column 33 is a columnar member provided on the upper side (positive z-axis direction side) surface of the rotating part 321 of the turntable 32. The support column 33 supports the seat surface 2 at the upper end portion 331 when the user sits on the seat surface 2 and the seat surface 2 is inclined. A plurality of support columns 33 are provided at equal intervals on the circumference on the upper side surface of the rotating part 321, but the installation positions can be set individually. Specifically, the support column 33 has the configuration shown in FIG. 3.

[0018] FIG. 3 is a diagram showing an example of the configuration of the support column 33a of the chair 100. The support column 33a includes an upper end portion 331a and a length adjustment portion 332a. The upper end portion 331a is, for example, a ball-shaped member, and supports the seat surface 2 when the seat surface 2 is inclined. By adopting a ball-shaped member for the upper end portion 331a, the turntable 32 can be rotated with little resistance even if the load of the user applied to the seat surface 2 is concentrated in the inclination direction. The length adjustment portion 332a is, for example, a screw type, and adjusts the length of the support column 33a.

[0019] Here, the support column 33b has the same configuration as the support column 33a, that is, it includes an upper end portion 331b and a length adjustment portion 332b. Also, the support column 33c also has the same configuration as the support column 33a, that is, it includes an upper end portion 331c and a length adjustment portion 332c.

[0020] Hereinafter, when there is no particular need to distinguish, the upper end portion 331a, the upper end portion 331b, and the upper end portion 331c are collectively referred to as the upper end portion 331, and the length adjustment portion 332a, the length adjustment portion 332b, and the length adjustment portion 332c are collectively referred to as the length adjustment portion 332.

[0021] Return to the description of FIG. 2. The vertical length of each of the plurality of support columns 33 is determined such that the seat surface 2 inclines at a predetermined angle from the reference state when the user is seated. Here, in order to generate the inclination, the vertical length of at least one of the plurality of support columns 33 is adjusted to be shorter than that of the other support columns 33. For example, the support column 33b is adjusted to have a shorter vertical length than the support column 33a. In other words, the length of the support column 33b is adjusted such that the distance Lb between the upper end portion 331b of the support column 33b and the lower side of the seat surface 2 is greater than the distance La between the upper end portion 331a of the support column 33a and the lower side of the seat surface 2. Also, the support column 33b is adjusted to have a shorter vertical length than the support column 33c. Here, the direction and angle for allowing the inclination of the seat surface 2 are determined according to the lengths of the support column 33a, the support column 33b, and the support column 33c. Further, it is preferable that the upper end portion 331a of the support column 33a and the upper end portion 331c of the support column 33c are in contact with the lower side of the seat surface 2.

[0022] Return to the description of FIG. 1. The power transmission mechanism 4 is composed of, for example, a belt and a pulley, or a chain and a sprocket, and transmits the power generated by the motor 5 to the turntable 32 of the support mechanism 3. Specifically, the power transmission mechanism 4 has the configuration shown in FIG. 4.

[0023] FIG. 4 is a diagram showing an example of the configuration of the power transmission mechanism 4 of the chair 100. As shown in FIG. 4, the power transmission mechanism 4 includes a motor 5 that rotates at a reduction ratio of 25:1, an 11-tooth pulley that interlocks with the rotation of the motor 5, a 40-tooth pulley, a 28-tooth pulley, and a configuration in which the gear portion 322 of the 47-tooth turntable 32 is connected by a belt. In the power transmission mechanism 4, since a very slow rotation requires a high reduction ratio, a very large reduction ratio of 1,260:1 is adopted.

[0024] Return to the description of FIG. 1. The motor 5 is, for example, an electric motor and generates power by rotation. The controller 6 controls the rotation of the motor 5. For example, the controller 6 can increase or decrease the rotation speed of the motor 5. Additionally, the controller 6 may switch the increase or decrease of the rotation speed of the motor 5 at predetermined intervals.

[0025] Subsequently, an example of the operation of the chair 100 according to the first embodiment will be described. The user sits on the seat surface 2 of the chair 100. At this time, the seat surface 2 is supported by the plurality of support columns 33 of the support mechanism 3. When at least one of the plurality of support columns 33 is shorter in length than the other support columns 33, the inclination of the seat surface 2 is allowed. Here, the direction and angle in which the inclination of the seat surface 2 is allowed are determined according to the respective lengths of the plurality of support columns 33.

[0026] Then, the user operates the controller 6. The controller 6 controls the rotation of the motor 5 based on the user's operation. The motor 5 generates power based on the control of the controller 6 and transmits the power to the turntable 32 of the support mechanism 4 via the power transmission mechanism 4. The rotating portion 321 of the turntable 32 rotates around the vertical axis based on the transmitted power and rotates the plurality of installed support columns 33 in the same direction. Then, the direction in which the inclination of the seat surface 2 is allowed changes with time.

[0027] As described above, the chair 100 according to the first embodiment can change the direction in which the inclination of the seat surface is allowed over time. These are ensured by the characteristics of the elastic support column 31 and the support column 33. That is, the elastic support column 31 that supports the seat surface 2 maintains the balance of the seat surface 2 when the bias of the load on the seat surface 2 is small. The support column 33 does not function to push up the seat surface 2, but supports the seat surface 2 when the seat surface 2 is inclined and constantly changes its direction over time. By doing so, the chair 100 allows the user various inclinations according to the bias of the center of gravity, and continuously causes the reflexive posture control movement associated therewith, so that a plurality of antigravity muscles (muscles corresponding to the inclination in the circumferential direction) necessary for the user to maintain the posture unconsciously can be effectively exercised. Note that the chair 100 can also prevent the user from being forced into an inappropriate inclination and being fixed in a bad posture.

[0028] Subsequently, the results of verifying that the chair 100 according to the first embodiment can effectively induce the movement of the user's antigravity muscles will be described with reference to FIGS. 5 to 15.

[0029] First, with reference to FIGS. 5 to 7, the arrangement of each sensor used in the verification and how to view the data obtained by them will be described. FIG. 5 shows an example of the arrangement of sensors installed on the seat surface 2 of the chair 100 in the verification. The acceleration sensor A is for measuring the inclination direction and inclination angle of the seat surface 2 from the horizontal plane at the time of sitting, and is installed on the lower side (negative z-axis direction side) of the seat surface 2. The surface pressure sensor B is for measuring the transition of the center of gravity position of the subject sitting on the seat surface 2 at the time of sitting, and is installed on the upper side (positive z-axis direction side) of the seat surface 2.

[0030] After the user sits on the seat surface 2 of the chair 100 and the chair 100 starts operating, measurement is performed by the acceleration sensor A. For example, the data shown in FIGS. 6 and 7 is obtained by the measurement. FIG. 6 is an inclination angle diagram showing an example of the inclination angle around the pitch axis and the inclination angle around the roll axis measured by the acceleration sensor A. The horizontal axis represents time. The vertical axis represents the inclination angle (deg). Here, the time on the horizontal axis is represented by the azimuth angle (deg) on the polar coordinate system of the reference point. The reference point is provided at a location where the support column 33 is on the upper surface of the rotating part 321 of the turntable 32. The horizontal axis indicates that the reference point makes one full turn counterclockwise from the rear direction of the user (-90 deg to 270 deg).

[0031] FIG. 7 is an inclination direction diagram showing the position of the reference point, the inclination direction, and the inclination angle of the seat surface 2 at a certain moment. The upward, leftward, downward, and rightward directions in the inclination direction diagram correspond to the front direction, left direction, rear direction, and right direction of the user, respectively. The orbit of the reference point is a circular orbit T (the circular part in FIG. 7). The straight line L extending from each point on the circular orbit T of the reference point represents the inclination direction and the inclination angle of the seat surface 2 at that moment. The inclination direction and the inclination angle correspond to the data shown in FIG. 6. The direction of the straight line L indicates the inclination direction, and the length of the straight line L indicates the inclination angle. In the following verification, the generated inclination direction and inclination angle of the seat surface 2 are represented by the inclination direction diagram.

[0032] Subsequently, the results of verifying the relationship between the number of support columns 33 in contact with the seat surface 2 of the chair 100 and the inclination direction of the seat surface 2 will be described with reference to FIGS. 8 to 10.

[0033] After the user sits on the seat surface 2 of the chair 100 and the chair 100 starts operating, measurements are taken by the acceleration sensor A. The chair 100 used for the measurement has different conditions regarding the number of support columns 33 in contact with the seat surface 2. The measured data is shown in FIG. 8.

[0034] FIG. 8 is an inclination direction diagram showing the inclination direction and the inclination angle for each number of support columns 33 in contact with the seat surface 2. FIG. 8A shows the results when measured on the chair 100 with zero support struts 33 in contact with the seat surface 2. For example, in the chair 100, the lengths of the support struts 33a, 33b, and 33c are adjusted so that the upper ends 331 (upper end 331a, upper end 331b, and upper end 331c) do not contact the lower side of the seat surface 2. That is, in the chair 100, the seat surface 2 is supported only by the elastic body struts 31.

[0035] FIG. 8B shows the results when measured on the chair 100 with two support struts 33 in contact with the seat surface 2 (that is, one support strut 33 not in contact with the seat surface 2). For example, in the chair 100, the lengths of the support struts 33a, 33b, and 33c are adjusted so that the upper end 331a of the support strut 33a and the upper end 331c of the support strut 33c contact the lower side of the seat surface 2, and only the upper end 331b of the support strut 33b does not contact the lower side of the seat surface 2. In the chair 100, when sitting, the inclination of the seat surface 2 is allowed according to the distance between the upper end 331b of the support strut 33b and the lower side of the seat surface 2.

[0036] FIG. 8C shows the results when measured on the chair 100 with three support struts 33 in contact with the seat surface 2. For example, in the chair 100, the lengths of the support struts 33a, 33b, and 33c are adjusted so that the upper ends 331 (upper end 331a, upper end 331b, and upper end 331c) contact the lower side of the seat surface 2. In the chair 100, the inclination of the seat surface 2 is not allowed when sitting.

[0037] In FIGS. 8A to 8C, the reference point of the turntable 32 is set on a specific support strut 33 (reference strut). In particular, in the chair 100 with two support struts 33 in contact with the seat surface 2 shown in FIG. 8B, the reference point of the turntable 32 is set on the support strut 33 not in contact with the seat surface 2.

[0038] From FIGS. 8A to 8C, the following was found. In FIG. 8A, it was found that the inclination of the seat surface 2 is biased in the left rear direction of the user at the reference point, and the inclination of the user's body appears in the inclination of the seat surface 2. In FIG. 8C, it was found that the inclination of the seat surface 2 occurs in the left direction of the user as a whole at the reference point, and the inclination of the seat surface 2 is suppressed to be small. On the other hand, in FIG. 8B, it was found that the inclination of the seat surface 2 occurs evenly in the entire circumferential direction of the seat surface 2 according to the position of the reference point. Since the inclination of the seat surface 2 does not deviate in one direction but occurs evenly in the entire circumferential direction, it was found that two support columns 33 in contact with the seat surface 2 are preferable. In addition, in FIG. 8B, it was confirmed that an inclination occurs in the direction of one support column 33 that does not contact the seat surface 2, that is, a support column 33 with a short length.

[0039] Subsequently, with reference to FIG. 9, the relationship between the vertical length of the support column 33 that does not contact the seat surface 2 and the inclination angle of the seat surface 2 in the chair 100 with two support columns 33 in contact with the seat surface 2 will be described.

[0040] After the user sits on the seat surface 2 of the chair 100 and the chair 100 starts operating, measurement is performed by the acceleration sensor A. In the chair 100 used for the measurement, the conditions of the vertical length of the support column 33 that does not contact the seat surface 2 are different. The measured data is shown in FIG. 9.

[0041] FIG. 9 is an inclination direction diagram showing the inclination direction and inclination angle for each length of the support column 33 that does not contact the seat surface 2. FIG. 9A shows the results for the chair 100 in which the length of the support column 33 that does not contact the seat surface 2 is adjusted so that the distance between the upper end portion 331 and the lower side of the seat surface 2 is 5.3 mm. FIG. 9B shows the results for the chair 100 in which the length of the support column 33 that does not contact the seat surface 2 is adjusted so that the distance between the upper end portion 331 and the lower side of the seat surface 2 is 18 mm.

[0042] As shown in FIGS. 9A and 9B, when the length of the support column 33 was adjusted so that the distance between the upper end portion 331 and the lower side of the seat surface 2 became from 5.3 mm to 18 mm, that is, when the length of the support column 33 was decreased, it was found that the inclination angle of the seat surface 2 became larger.

[0043] Subsequently, with reference to FIGS. 10 to 11, the results of verifying the relationship between the inclination of the seat surface 2 of the chair 100 and the amount of the user's center of gravity movement on the seat surface 2 will be described.

[0044] After the user sat on the seat surface 2 of the chair 100 and the chair 100 started operating, measurements were taken by the acceleration sensor A and the surface pressure sensor B. In the measurement, two chairs 100 in which the support columns 33 in contact with the seat surface 2 were used. In the measured chair 100, the length of the support column 33 not in contact with the seat surface 2 and the conditions of the subject were different. The measurement results are shown in FIGS. 10 and 11.

[0045] FIG. 10 is an inclination direction diagram showing the inclination direction and inclination angle of the seat surface 2 for each condition of the length of the support column 33 not in contact with the seat surface 2 and the subject. FIG. 11 is a diagram showing the amount of the subject's center of gravity movement on the seat surface 2 for each condition of the length of the support column 33 not in contact with the seat surface 2 and the subject.

[0046] FIGS. 10A and 11A show the results for the chair 100 in which the length of the support column 33 not in contact with the seat surface 2 was adjusted so that the distance between the upper end portion 331 and the lower side of the seat surface 2 became 5.3 mm. That is, the results are for the chair 100 adjusted so that the angle allowing the inclination of the seat surface 2 (inclination allowable angle) becomes 2 deg. Further, FIGS. 10A and 11A show the results when a 40 kg sandbag was placed on the seat surface 2 of the chair 100.

[0047] Figures 10B and 11B show the results for chair 100 in which the length of support strut 33, which does not contact seating surface 2, is adjusted such that the distance between the upper end portion 331 and the lower side of seating surface 2 is 5.3 mm. That is, they show the results for chair 100 in which the inclination of seating surface 2 is adjusted so that the allowable inclination angle is 2 deg. Figures 10B and 11B show the results when a human, i.e., a user, is seated on seating surface 2 of chair 100.

[0048] Figures 10C and 11C show the results for chair 100 in which the length of support strut 33, which does not contact seating surface 2, is adjusted such that the distance between the upper end portion 331 and the lower side of seating surface 2 is 18 mm. That is, they show the results for chair 100 in which the allowable inclination angle of seating surface 2 is adjusted to 8 deg. Figures 10C and 11C show the results when a human is seated on seating surface 2 of chair 100.

[0049] The amount of center of gravity movement in Figures 11A, 11B, and 11C indicates the transition of the center of gravity position on seating surface 2. The transition of the center of gravity position uses, as the origin, the center of gravity position immediately after the sandbag is placed or the center of gravity position immediately after a human sits down, and shows the amount of change from the origin. One scale division is 5 mm.

[0050] From Figures 11A, 11B, and 11C, the following was found. As shown in Figures 11A and 11B, even when the allowable inclination angle of seating surface 2 is the same 2 deg, it was found that the deviation of the center of gravity from the origin is greater when the sandbag is placed on seating surface 2 than when a human sits on seating surface 2. Therefore, it was found that the seated human has effective center of gravity control. As shown in Figures 11A and 11C, it was found that when the allowable inclination angle of seating surface 2 is adjusted from 2 deg to 8 deg, the center of gravity movement of the human finally becomes about the same as that of the sandbag. From this as well, it was found that the seated human always has effective center of gravity control.

[0051] Subsequently, the results of verifying the relationship between the center of gravity control due to the inclination of seating surface 2 and the trunk movement of the user, i.e., the movement of the spine, will be described using Figures 12 to 15.

[0052] After the user sat on the seat surface 2 of the chair 100 and the chair 100 started operating, the seat surface inclination and the pressure distribution on the seat surface were measured by the acceleration sensor A and the surface pressure sensor B, respectively. In addition, the movement of the representative points on the spine of the user sitting on the seat surface 2 was measured by motion capture. In the measured chair 100, the number of support columns 33 in contact with the seat surface 2 is different. The measurement results are shown in FIGS. 12, 13, 14, and 15.

[0053] FIG. 12 is an inclination direction diagram showing the inclination direction and inclination angle of the seat surface 2 for each number of support columns 33 not in contact with the seat surface 2. FIG. 13 is a diagram showing the amount of center of gravity movement of the subject on the seat surface 2 for each number of support columns 33 not in contact with the seat surface 2. FIG. 14 is a diagram showing the movement of the representative points P3, P4, P9, P10, and P12 on the spine of the user for each number of support columns 33 not in contact with the seat surface 2.

[0054] FIGS. 12A, 13A, and 14A are the results of the chair 100 with 0 support columns 33 in contact with the seat surface 2. On the other hand, FIGS. 12B, 13B, and 14B are the results of the chair 100 with 2 support columns 33 in contact with the seat surface 2.

[0055] FIGS. 14A and 14B are diagrams showing the movement of the representative points P3, P4, P9, P10, and P12 on the spine of the user, respectively. The horizontal axis represents the azimuth angle (deg) in the polar coordinate system of the reference point of the turntable 32. The horizontal axis indicates that the reference point makes one full turn counterclockwise from the rear direction of the user (-90 deg to 270 deg). The vertical axis represents the movement distance (mm) in the left direction of the user from the origin in the coordinate system fixed in space for each of the representative points P3, P4, P9, P10, and P12 on the spine of the subject. FIG. 14C is a diagram showing the positions of the representative points P3, P4, P9, P10, and P12 on the spine of the user.

[0056] From FIGS. 12A and 12B, it was found that by changing the number of support struts 33 in contact with the seat surface 2 from 0 to 2, the inclination of the seat surface 2 occurred evenly in the circumferential direction of the seat surface 2 according to the position of the reference point. And from FIGS. 13A and 13B, it was found that by changing the number of support struts 33 in contact with the seat surface 2 from 0 to 2, the center-of-gravity movement of the user occurred. From FIGS. 14A and 14B, it was found that by changing the number of support struts 33 in contact with the seat surface 2 from 0 to 2, the movement of the positions of the representative points P3, P4, P9, P10, and P12 on the user's spine occurred more. That is, it was found that the movement of the user's spine was induced. Therefore, it was found that by changing the number of support struts 33 in contact with the seat surface 2 from 0 to 2, the inclination of the seat surface 2 occurred evenly in the circumferential direction of the seat surface 2, and as a result, the movement of the user's spine due to the center-of-gravity movement of the user was induced.

[0057] In addition, the movement of the representative points on the user's spine in the case of the chair 100 with two support struts 33 in contact with the seat surface 2 was verified in detail. FIG. 15 is a diagram showing the relative positions of the representative points P3, P4, P9, P10, and P12 on the user's spine with respect to P12. The horizontal axis of each graph indicates the relative left-right distance or the front-back distance of the user with respect to P12. The vertical axis of each graph indicates the relative height with respect to P12. Each graph is arranged in the order of the azimuth angle (deg) on the polar coordinate system of the reference point of the corresponding turntable 32.

[0058] From FIG. 15, it was found that the user's spine moved back and forth and left and right by the center-of-gravity control accompanying the inclination of the seat surface 2. The user did not consciously move the trunk during the test, but such a result was obtained. Since the muscles that change the shape of the spine are the action of the antigravity muscles, which are deep muscles, it is considered that the activity of the deep muscles is induced unconsciously.

[0059] (Second Embodiment) Next, with reference to FIG. 16, the configuration of the chair 200 according to the second embodiment will be described. The chair 200 according to the second embodiment further includes a body support portion 7 that supports the user's body, in addition to the chair 100 according to the first embodiment. The body support portion 7 supports, for example, the user's back, upper arm, head, or torso. The point (support point) where the body support portion 7 supports the user's body becomes a point that hinders the user's movement. Therefore, the movement of the user's trunk changes due to the body support portion 7. The user's trunk movement (= movement of the spine) generated by the support of the body support portion 7 changes as shown in FIG. 16, for example, depending on the position of the support point.

[0060] FIG. 16 is a diagram showing the movement of the user's spine for each support point by the body support portion 7. FIG. 16A shows the movement of the user's spine when there is no support point by the body support portion 7. FIG. 16B shows the movement of the user's spine when the support point by the body support portion 7 is the back. FIG. 16C shows the movement of the user's spine when the support point by the body support portion 7 is the upper arm. FIG. 16D shows the movement of the user's spine when the support point by the body support portion 7 is the head. FIG. 16E shows the movement of the user's spine when the support point by the body support portion 7 is the torso.

[0061] As shown in FIGS. 16A to 16E, it is conceivable that the movement of the user's spine changes around the support point. As a result, by changing the muscles that become active, it is possible to expect the induction of more diverse movements.

[0062] Note that the present invention is not limited to the above-described embodiments, and can be appropriately modified without departing from the gist.

[0063] (Modification example) Note that the elastic coefficient of each elastic body column 31 may be set and may be different for each elastic body column 31. The number of elastic body columns 31 may be any number as long as the balance of the seat surface 2 can be maintained without the support of the support column 33. The thickness of each elastic body column 31 may be set and may be different for each elastic body column 31.

[0064] The number of support columns 33 may be any number as long as it is three or more. Also, there is no limit to the number of support columns 33 that are brought into contact with the lower side of the seat surface 2. The length adjustment portion 332 of the support column 33 is not limited to a screw type as long as it can sufficiently support the load from the seat surface 2 due to sitting. Further, the length adjustment portion 332 may employ an actuator for adjusting the length of the support column 33 and perform control via a controller. In that case, it is also possible to allow the inclination of the seat surface without using the turntable 32 by synchronously controlling the lengths of the plurality of support columns 33. The length adjustment portion 332 may further create an allowable inclination according to the user's state by acquiring information from an acceleration sensor A that measures the inclination of the seat surface 2 and a surface pressure sensor B that measures the surface pressure of the seat surface 2.

[0065] The power transmission mechanism 4 is not limited to a belt and pulley, or a chain and sprocket. Transmission by a gear train may also be used. The motor 5 is not limited to an electric motor as long as sufficient output can be obtained to drive the support mechanism 3 against the load due to sitting.

[0066] Also, as shown in FIG. 17, a control system 500 including a control device 8 for controlling the chair 100 may be configured.

[0067] The control device 8 is an arithmetic device, a server, etc., communicates with the chair 100 by wireless communication or wired communication, and controls the rotation of the motor 5 of the chair 100. Specifically, the control device 8 receives data regarding the operating status from the chair 100. Also, the control device 8 transmits a control signal to the chair 100 and controls the rotation of the motor 5. For example, the control device 8 can increase or decrease the rotation speed of the motor 5. Note that the control device 8 may switch the increase or decrease of the rotation speed of the motor 5 at predetermined intervals. Here, the control device 8 may be used instead of the controller 6 of the chair 100.

[0068] The control device 8 may control a plurality of chairs 100. For example, the control device 8 controls the chairs 100 at home, the chairs 100 at the workplace, the chairs 100 at a sports facility, and the chairs 100 at a care facility.

[0069] The control device 8 is constituted by hardware or software, or both, and may be constituted by one piece of hardware or software, or may be constituted by a plurality of pieces of hardware or software. The control process of the control device 8 may be realized by a computer having a processor such as a CPU (Central Processing Unit) and a memory which is a storage device. For example, a program for performing the control process in the embodiment may be stored in the memory, and each function may be realized by executing the program stored in the memory by the processor.

[0070] These programs, when loaded into a computer, include a group of instructions (or software code) for causing the computer to perform one or more functions described in the embodiment. The program may be stored in a non-transitory computer-readable medium or a tangible storage medium. By way of example and not limitation, the computer-readable medium or tangible storage medium includes random-access memory (RAM), read-only memory (ROM), flash memory, solid-state drive (SSD), or other memory technologies, CD-ROM, digital versatile disc (DVD), Blu-ray (registered trademark) disc, or other optical disc storage, magnetic cassette, magnetic tape, magnetic disk storage, or other magnetic storage devices. The program may be transmitted on a transitory computer-readable medium or a communication medium. By way of example and not limitation, the transitory computer-readable medium or communication medium includes electrical, optical, acoustic, or other forms of propagated signals.

Explanation of Reference Numerals

[0071] 1 Base 2 Seat surface 3 Support mechanism 4 Power transmission mechanism 5 Motor 6 Controller 7 Body support part 8 Control device 31, 31a, 31b, 31c Elastic body struts 32 Turntable 33, 33a, 33b, 33c Support struts 100, 200 Chairs 321 Rotating part 322 Gear part 323 Rotating base part 331, 331a, 331b, 331c Upper ends 332, 332a, 332b, 332c Length adjustment parts 500 Control system

Claims

1. A base, a seating surface located above the base on which a user sits, an elastic body support column that connects the base and the seating surface, keeps the seating surface in a reference state, and allows the seating surface to tilt from the reference state according to the force applied to the seating surface by the user's sitting, a turntable installed above the base and rotating around a vertical axis based on power, a plurality of support columns with different lengths in the vertical direction installed above the turntable and supporting the seating surface at the upper end when the seating surface tilts from the reference state, a motor that generates the power, and among the plurality of support columns, the support column with the longest length in the vertical direction is set to a length such that the upper end contacts the lower side of the seating surface when the seating surface is in the reference state Chair.

2. The vertical length of each of the plurality of support columns is determined such that the seating surface tilts by a predetermined angle from the reference state The chair according to claim 1.

3. Further comprising a controller that controls the rotation of the motor The chair according to claim 1.

4. Each of the plurality of support columns is provided with a mechanism capable of adjusting the length in the vertical direction The chair according to claim 1.

5. Further comprising a body support portion that supports a part of the user's body, The body support portion fixes at least one of the user's back, upper arm, head, and torso The chair according to claim 1.

6. A computer, a base, a seating surface located above the base on which a user sits, an elastic body support column that connects the base and the seating surface, keeps the seating surface in a reference state, and allows the seating surface to tilt from the reference state according to the force applied to the seating surface by the user's sitting, a turntable installed above the base and rotating around a vertical axis based on power, a plurality of support columns with different lengths in the vertical direction installed above the turntable and supporting the seating surface at the upper end when the seating surface tilts from the reference state, a motor that generates the power, and controls the rotation of the motor of the chair in which among the plurality of support columns, the support column with the longest length in the vertical direction is set to a length such that the upper end contacts the lower side of the seating surface when the seating surface is in the reference state Control method.

7. A base, a seating surface located above the base on which a user sits, An elastic body support column that connects the base and the seat surface, maintains the seat surface in a reference state, and allows the seat surface to tilt from the reference state in response to the force applied to the seat surface by the user's sitting; A turntable installed on the upper side of the base and rotating around a vertical axis based on power; A plurality of support columns with different lengths in the vertical direction, installed on the upper side of the turntable and supporting the seat surface at the upper end when the seat surface tilts from the reference state; A motor that generates the power; and Causing a computer to execute a process of controlling the rotation of the motor of a chair in which the longest support column in the vertical direction among the plurality of support columns is set to a length such that the upper end contacts the lower side of the seat surface when the seat surface is in the reference state Program.

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